1,4-Benzodiazepines having CNS drug tranquilizer utilities have been known since at least 1966. Examples of well known drug products of this type include diazepam and chlordiazepoxide hydrochloride, which are sold under the familiar trademarks VALIUM.RTM. and LIBRIUM.RTM.. Research has continued over the years to find other new and useful 1,4-benzodiazepines which would be competitive with diazepam and chlordiazepoxide hydrochloride, or have different medicinal uses.
Research has prepared compounds varying the 1,4-benzodiazepine structure in the 5-position, putting in different aromatic type heterocyclic rings in the ring C position (5-position). See Archer et al U.S. Pat. No. 3,236,838 and Felix et al U.S. Pat. No. 3,546,212. Also, the Griot U.S. Pat. No. 3,414,563 suggests putting a simple amino group (--NH.sub.2) or an --NRoR.sub.1, or an ##STR2## ring group in the 5-position of the 1,4-benzodiazepine structure. To our knowledge, however, none of these 5-amino 1,4-benzodiazepines have ever become a commercial or useful product to any significant extent.
In my prior U.S. Pat. No. 3,714,178 I have described some 6,7-dihydro-7-alkyl-5H-1,2,4-triazolo[4,3-d][1,4]benzodiazepines of the formula ##STR3## which contain a triazolo ring on the "lower" side of the 1,4-benzodiazepine structure, and U.S. Pat. No. 3,717,654 which describes some 2,5,6,7-tetrahydro-7-alkyl-3H-s-triazolo[4,3-d][1,4]benzodiazepin-3-ones of the formula ##STR4## as sedatives, hypnotics, anit-convulsants, tranquilizers and muscle relaxant drugs for mammals and birds and as feed growth additives in livestock and poultry.
My U.S. Pat. No. 3,896,109 describes some 2,3-dihydro-1H-1,4-benzodiazepines of the formula ##STR5## wherein R.sub.2 and R.sub.3 can each be alkyl or R.sub.2 and R.sub.3 taken together with the nitrogen to which they are bonded complete a 4-phenylpiperazino group, which compounds have CNS sedative and tranquilizing properties. This above chemistry is now published in Tetrahedron Letters, No. 20, pp. 1609-1612 (1971) in an article entitled "A Synthetic Approach to New 1,4-Benzodiazepine Derivatives", by Jackson B. Hester, Jr., et al.
More recently, Hester U.S. Pat. No. 3,987,052 issued which discloses new 6-phenyl-4H-s-triazolo[4,3-a][1,4]benzodiazepines, e.g., 8-chloro-1-methyl-6-(o-chlorophenyl)-4H-s-triazolo[4,3-a][1,4]benzodiazepi nes, and the like, which is an important new hypnotic type sedative CNS drug.
However, none of the above 1,4-benzodiazepine prior art patents and references disclose or suggest the new compounds of this invention or what their pharmacological usefulness will be.